Course Organization
Lecture 1/Part 1
1
Outline
 About me
 About the course
 Lectures
 Seminars
 Evaluation
 Literature
2
About me:
Ing. RNDr. Barbora Bühnová, Ph.D.
 Industrial experience
 Research
 Quality of software architecture
 LaSArIS
 Teaching
 Courses on UML, Java, .NET, Automata and grammars,
Algorithm design, and others
 Colaboration with students
 Seminar tutoring
 Bachelor/Master theses
3
About the course:
PB007 Software Engineering I
 Lectures
1. Software process, role of the UML language.
2. Functional requirements specification, UML Use Case diagram.
3. Nonfunctional requirements specification, UML Activity diagram.
4. System analysis and design, structured vs. object-oriented A&D.
5. Object oriented analysis, UML Class, Object and Interaction diagrams.
6. Structured analysis, data modelling, ERD.
7. System design and attributes of a high-quality design, UML State diagram.
8. Software architecture, UML Component and Deployment diagram.
9. User interface design.
10. Testing, verification and validation.
11. Operation, maintenance and system evolution.
12. Software development management - processes, tools and frameworks.
13. Advanced software engineering techniques.
4
About the course:
PB007 Software Engineering I
 Seminars
1. Visual Paradigm introduction, project assignment.
2. Project start, initial Use Case diagram.
3. Detailed Use Case diagram, textual specification of UC
4. Specification of use cases (textual if not finished, Activity diagram).
5. Analytical Class diagram, Object diagram.
6. Finalization of analytical Class diagram, Use Case diagram update.
7. Data modelling, Entity Relationship diagram.
8. Refinement of use cases with Interaction diagrams.
9. Finalization of Interaction diagrams, Class diagram update.
10. State diagram.
11. Design-level Class diagram, interfaces, implementation details.
12. User interface design.
13. Packages, Component diagram, Deployment diagram.
5
About the course:
PB007 Software Engineering I
 Lectures
 13 teaching weeks + 1 week free
 Seminars
 Team project on UML modelling
 2-3 students per team
 Obligatory attendance and weekly task delivery
 Penalty for absence (-5/-10) and task delivery (-5/-10 points)
 Evaluation
 Exam = test (50 points) + on-site modelling (50 points)
 Grades: 90-100A, 80-89 B, 70-79 C, 60-69 D, 50-59 E, 0-49 F
6
Literature
 Software Engineering, 9/E
 Author: Ian Sommerville
 Publisher: Addison-Wesley
 Copyright: 2011
 UML 2 and the Unified Process, 2/E
 Author: Jim Arlow and Ila Neustadt
 Publisher: Addison-Wesley
 Copyright: 2005
7
Software process
Lecture 1/Part 2
Chapter 2 Software Processes 8
Outline
 Software engineering
 Software process activities
 Software process models
Chapter 2 Software Processes 9
Software engineering
 The economies and human lifes of ALL developed
nations are dependent on software.
 More and more systems are software controlled
 Software engineering is concerned with theories,
methods and tools for professional software
development.
 Software engineering is concerned with cost-effective
development of high-quality software systems .
Chapter 1 Introduction
Frequently asked questions about software
engineering
Chapter 1 Introduction 11
Question Answer
Whatis software? Computer programs and associated documentation.
Software products may be developed for a particular
customerormay be developedfora general market.
Whatare the attributes of good software? Good software should deliver the required functionality
and performance to the user and should be
maintainable, dependable and usable(amongothers).
Whatis software engineering? Software engineering is an engineering discipline that is
concerned with all aspects of software production.
What are the fundamental software
engineeringactivities?
Software specification, software development, software
validation and softwareevolution.
What is the difference between software
engineeringand computer science?
Computer science focuses on theory and fundamentals;
software engineering is concerned with the practicalities
of developing and delivering useful software.
What is the difference between software
engineeringand system engineering?
System engineering is concerned with all aspects of
computer-based systems development including
hardware, software and process engineering. Software
engineeringis part of this more general process.
Software versus System engineering
Chapter 10 Sociotechnical Systems 12
Software products
 Generic products
 Stand-alone systems that are marketed and sold to any
customer who wishes to buy them.
 Examples – PC software such as graphics programs, project
management tools; CAD software.
 Customized products
 Software that is commissioned by a specific customer to meet
their own needs.
 Examples – embedded control systems, air traffic control
software, traffic monitoring systems.
Chapter 1 Introduction 13
Application types
 Stand-alone applications
 Interactive transaction-based applications
 Embedded control systems
 Batch processing systems
 Entertainment systems
 Systems for modeling and simulation
 Data collection and monitoring systems
 Systems of systems
Chapter 1 Introduction 14
Software engineering fundamentals
 Some fundamental principles apply to all types of
software system, irrespective of the development
techniques used:
 Systems should be developed using a managed and
understood development process. Of course, different
processes are used for different types of software.
 Dependabilityand performance are important for all types of
system.
 Understandingand managing the software specification and
requirements (what the software should do) are important.
 Where appropriate, you should reuse software that has already
been developed rather than write new software.
Chapter 1 Introduction 15
The software process
 A structured set of activities required to develop a
software system.
 Many different software processes but all involve:
 Specification
 Development
• Analysis and design
• Implementation
 Validation
 Evolution
 A software process model is an abstract representation
of a process – from some particular perspective.
Chapter 2 Software Processes 16
Software process activities
 Software specification, where customers and engineers
define the software and the constraints on its operation.
 Software analysis and design, where the requirements
are refined into system design.
 Software implementation, where the software is
implemented.
 Software validation, where the software is checked to
ensure that it is what the customer requires.
 Software evolution, where the software is modified to
reflect changing customer and market requirements.
17Chapter 2 Software Processes
Software process models
 The waterfall model
 Plan-driven model. Separate and distinct phases of specification
and development.
 Incremental development
 Specification, development and validation are interleaved. May
be plan-driven or agile (respecting agile development principles).
 Reuse-oriented software engineering
 The system is assembled from existing components. May be
plan-driven or agile.
 In practice, most large systems are developed using a
process that incorporates elements from all of these
models.
Chapter 2 Software Processes 18
The waterfall model
Chapter 2 Software Processes 19
Waterfall model problems
 Inflexible partitioning of the project into distinct stages
makes it difficult to respond to changing customer
requirements.
 Therefore, this model is only appropriate when the requirements
are well-understood and changes will be fairly limited during the
design process.
 Few business systems have stable requirements.
 The waterfall model is mostly used for large systems
engineering projects where a system is developed at
several sites, and for generic products.
 In those circumstances, the plan-driven nature of the waterfall
model helps coordinate the work.
Chapter 2 Software Processes 20
Incremental development
Chapter 2 Software Processes 21
Incremental development benefits
 The cost of accommodating changing customer
requirements is reduced.
 The amount of analysis and documentationthat has to be
redone is much less than is required with the waterfall model.
 It is easier to get customer feedback on the development
work that has been done.
 Customers can comment on demonstrations of the software and
see how much has been implemented.
 More rapid delivery and deployment of useful software to
the customer is possible.
 Customers are able to use and gain value from the software
earlier than is possible with a waterfall process.
Chapter 2 Software Processes 22
Incremental development problems
 The process is not visible.
 Managers need regular deliverables to measure progress. If
systems are developed quickly, it is not cost-effective to produce
documents that reflect every version of the system.
 System structure tends to degrade as new increments
are added.
 Unless time and money is spent on refactoring to improve the
software, regular change tends to corrupt its structure.
Incorporatingfurther software changes becomes increasingly
difficult and costly.
Chapter 2 Software Processes 23
Reuse-oriented software engineering
 Based on systematic reuse where systems are
integrated from existing components or COTS
(Commercial-off-the-shelf) systems.
 Process stages
 Component analysis;
 Requirements modification;
 System design with reuse;
 Development and integration.
 Reuse is now the standard approach for building many
types of business system
Chapter 2 Software Processes 24
Reuse-oriented software engineering
Chapter 2 Software Processes 25
Key points
 There are many different types of system and each
requires appropriate software engineering tools and
techniques for their development.
 The fundamental ideas of software engineering are applicable to
all types of software system.
 Software engineering is an engineering discipline that is
concerned with all aspects of software production.
 The high-level activities of specification, development (analysis
and design, and implementation), validation and evolution are
part of all software processes.
Chapter 1 Introduction 26
Key points
 Software processes are the activities involved in
producing a software system. Software process models
are abstract representations of these processes.
 General process models describe the organization of
software processes. Examples of these general models
include the ‘waterfall’ model, incremental development,
and reuse-oriented development.
Chapter 2 Software Processes 27
UML in Software Development
Lecture 1/Part 3
28Chapter 5 System modeling
Outline
 System modeling
 Structural models
 Interaction models
 Behavioral models
29Chapter 5 System modeling
System modeling
 System modeling is the process of developing abstract
models of a system, with each model presenting a
different view or perspective of that system.
 System modeling has now come to mean representing a
system using some kind of graphical notation, which is
now almost always based on notations in the Unified
Modeling Language (UML).
 System modelling helps the analyst to understand the
functionality of the system and models are used to
communicate with colleagues and customers.
Chapter 5 System modeling 30
System perspectives
 An external perspective, where you model system
boundary, the context and/or environment of the system.
 A structural perspective, where you model the
organization of a system or the structure of the data that
is processed by the system.
 An interaction perspective, where you model the
interactions between a system and its environment, or
between the components of a system.
 A behavioral perspective, where you model the
dynamic behavior of the system and how it responds to
events.
Chapter 5 System modeling 31
UML diagram types
 External perspective
 Use case diagram
 Structural perspective
 Class diagram, Object diagram, Component diagram, Package
diagram, Deployment diagram, Composite structure diagram
 Interaction perspective
 Sequence diagram, Communication diagram, Interaction
overview diagram, Timing diagram
 Behavioral perspective
 Activitydiagram, State diagram
Chapter 5 System modeling 32
Popular UML diagrams
 Use case diagrams, which show the interactions
between a system and its environment.
 Class diagrams, which show the object classes in the
system and the associations between these classes.
 Sequence diagrams, which show interactions between
actors and the system and between system components.
 Activity diagrams, which show the activities involved in
a process or in data processing.
Chapter 5 System modeling 33
UML Use case diagram:
Medical receptionist in health care system
Chapter 5 System modeling 34
UML Class diagram:
Health care system
Chapter 5 System modeling 35
UML Sequence diagram:
View patient information in health care system
Chapter 5 System modeling 36
UML Activity diagram:
Process model of involuntary detention
Chapter 5 System modeling 37
Key points
 A model is an abstract view of a system that ignores system
details. Complementary system models can be developed to
show the system’s context, structure, behavior and
interactions.
 Context models show how a system that is being modeled is
positioned in an environment with other systems.
 Structural models show the organization and architecture of
a system. Class diagrams are used to define the static
structure of classes in a system and their associations.
 Interaction models are used to describe the interactions
between system elements and Behavioral models to detail
the internal dynamic behavior of system elements/processes.
Chapter 5 System modeling 38